Wraparound plastic corrugated case

ABSTRACT

A plastic corrugated case is provided. The case is made of at least one extruded sheet having, in an unfolded state, an extrusion direction and a transverse direction perpendicular to the extrusion direction. The sheet has a cross-sectional profile parallel to the transverse direction, the cross-sectional profile having a first section, and a second section different from the first section.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to plastic cases, and moreparticularly to plastic corrugated cases.

2. Related Art

Cases or boxes are often used to ship and display multiple smallercontainers of a products. For example, motor oil is usually sold in onequart plastic containers that are shipped in cases that hold either 6 or12 of the one quart plastic containers. These cases are usuallyconstructed of corrugated cardboard. If the cardboard cases become wetthrough contact with rain or other liquid, they become very weak andoften fail. Also, to be opened, the cardboard cases often must be cutwith a knife. This can lead to accidental cutting of the productcontainers within the case.

BRIEF SUMMARY OF THE INVENTION

In summary, embodiments of the invention provide a corrugated plasticcase that has differing cross sections so that sections of the case thatrequire more strength are stronger while sections requiring lessstrength use less plastic material.

Particular embodiments of the invention provide a plastic corrugatedcase, having at least one extruded sheet having, in an unfolded state,an extrusion direction and a transverse direction perpendicular to theextrusion direction, the sheet having a cross-sectional profile parallelto the transverse direction, the cross-sectional profile having a firstsection, and a second section different from the first section.

Other embodiments of the invention provide a one piece plasticcorrugated case having, in an unfolded state, an extrusion direction.The case has a bottom panel having a cross-sectional profileperpendicular to the extrusion direction; a front panel attached to thebottom panel and having a cross-sectional profile perpendicular to theextrusion direction; a back panel attached to the bottom panel andhaving a cross-sectional profile perpendicular to the extrusiondirection; a right side panel attached to at least one of the frontpanel, the back panel or the bottom panel and having a cross-sectionalprofile perpendicular to the extrusion direction; a left side panelattached to at least one of the front panel, the back panel or thebottom panel and having a cross-sectional profile perpendicular to theextrusion direction; and a top panel attached to at least one of thefront panel, the back panel, the right side panel or the left side paneland having a cross-sectional profile perpendicular to the extrusiondirection. The case is, in the unfolded state, a single piece ofplastic, and at least one of the cross-sectional profiles changes alonga direction perpendicular to the extrusion direction.

Other embodiments of the invention provide a method of producing aplastic corrugated case. The method includes extruding a first sheethaving, in an unfolded state, an extrusion direction and a transversedirection perpendicular to the extrusion direction. The extrusion causesthe first sheet to have a cross-sectional profile parallel to thetransverse direction, the cross-sectional profile having a firstsection, and a second section different from the first section. Themethod further includes folding the first sheet to form at least a partof the case; and attaching portions of the first sheet to other portionsof the first sheet or to portions of a second sheet to maintain the casein a folded state.

Further objectives and advantages, as well as the structure and functionof preferred embodiments will become apparent from a consideration ofthe description, drawings, and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the following, more particular description of preferredembodiments of the invention, as illustrated in the accompanyingdrawings wherein like reference numbers generally indicate identical,functionally similar, and/or structurally similar elements.

FIG. 1 is a perspective view of an example of a first embodiment of acase according to the invention;

FIG. 2 is a plan view of the case of FIG. 1 in an unfolded state;

FIG. 3 is a perspective view of a corner detail of the case shown inFIGS. 1 and 2;

FIG. 4 is a plan view of the corner detail shown in FIG. 3;

FIG. 5 is a plan view of a second embodiment of the invention; and

FIG. 6 is plan view of a third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention are discussed in detail below. Indescribing embodiments, specific terminology is employed for the sake ofclarity. However, the invention is not intended to be limited to thespecific terminology so selected. While specific exemplary embodimentsare discussed, it should be understood that this is done forillustration purposes only. A person skilled in the relevant art willrecognize that other components and configurations can be used withoutparting from the spirit and scope of the invention. All references citedherein are incorporated by reference as if each had been individuallyincorporated.

The above described problems with cardboard boxes can be eliminated byusing plastic corrugated cases in accordance with the invention. Suchplastic corrugated cases can be made from extruded sheets of corrugatedplastics. However, with sheets of corrugated plastic having a uniformcross section, in order to make particular sections of the plasticcorrugated sheet strong enough, other sections of the plastic corrugatedsheet will be stronger then necessary. This results in using moreplastic material than necessary and, therefore, a higher cost thannecessary. Particular embodiments of the invention solve this problemassociated with plastic corrugated sheets having a uniform cross sectionby altering the cross section of the plastic corrugated sheet so thatparticular sections of the plastic corrugated sheet are provided withonly as much material as those sections require in the finished case.

FIG. 1 shows a case 1 in accordance with an exemplary embodiment of theinvention. FIG. 2 shows a sheet of corrugated plastic that can be foldedto form case 1. As shown in FIG. 1, case 1 has a bottom 10, a top 20, afront 30, a back 40, a left side 50 and a right side 60.

The sheet shown in FIG. 2 has a bottom panel 100 that forms bottom 10 ofcase 1. Top 20, front 30 and back 40 are formed by top panel 200, frontpanel 300 and back panel 400, respectability. Attached to front panel300 are right side panel 310 and left side panel 320. Similarly,attached to back panel 400 are right side panel 410 and left side panel420. To assemble case 1, right side panel 310 is folded along fold line301 so that right side panel 310 forms a 90° angle with front panel 300.Similarly, left side panel 320 is folded along fold line 302 such thatleft side panel 320 forms a 90° angle with front panel 300. Front panel300 is then folded along fold line 303 to form a 90° angle with bottompanel 100. At this point, a lower edge of left side panel 320 rests nearfold line 102 of bottom panel 100 and a lower edge right side panel 310rests near fold line 101 of bottom panel 100. Next, right side panel 410is folded along fold line 401 to form a 90° angle with back panel 400and left side panel 420 is folded along fold line 402 to form a 90°angle with back panel 400. Back panel 400 is then folded along fold line403 to form a 90° angle with bottom panel 100. At this point, the loweredge of left side 420 rests on, or is proximate to, fold line 102 and alower edge of right side panel 410 rests on, or is proximate to, foldline 101. A right flap 110 is then folded along fold line 101 andsecured to right side panels 310, 410. Similarly, a left flap 120 isfolded along fold line 102 and secured to left side panels 320, 420.Right flap 110 and left flap 120 can be secured by, for example, plasticwelding or an adhesive. In this assembled position, an edge 311 of rightside panel 310 preferably contacts, and is adhere to, an edge 411 ofright side panel 410. Similarly, an edge 321 of left side panel 320preferably contacts, and is adhered to, an edge 421 of left side panel420. At this point, case 1 is ready to be filled with product.

After case 1 is filled with the product to be sold in case 1, top panel200 is folded along fold line 203 to form a 90° angle with back panel400 and closes case 1. Top panel 200 is secured in place by folding afront flap 210 along a fold line 204 and bonding front flap 210 to frontpanel 300 as shown in FIG. 1. A right side flap 220 is folded along afold line 201 to form a 90° angle with top panel 200 and is bonded toright side panels 310, 410. Similarly, a left flap 230 if folded along afold line 202 to form a 90° angle with top panel 200 and is bonded toleft side panels 320, 420.

Right flap 220 and left flap 230 are provided with a right handle 225,and a left handle 235, respectively. Handles 225, 235 can be folded awayfrom right side 60 and left side 50, respectively, to facilitate liftingof case 1. In this example, handles 225 and 235 are provided withgrooves 227 and 237, respectively, to add strength to the handles.

In accordance with the invention, particular areas of case 100 arestrengthened to sustain the loads placed on case 1 during use, whileother portions of case 1 do not require strengthening. In FIGS. 2 and 3,strengthened areas are shown by cross hatching. One example ofstrengthening in accordance with the invention is shown in FIGS. 3 and4. In this example, the corrugated plastic cross section in strengthenedareas 440 and 445 have thicker top and bottom panels and thicker websbetween the panels. This thickening is provided by using, for example,different die sizes during the extrusion process. In addition to thethickening discussed above, left side panel 420 and left side panel 320are further strengthened by grooves 425 and 325, respectably. As shownin FIG. 2, similar grooves 315 and 415 are provided in right side panel310 and right side panel 410, respectably. FIG. 3 also shows astrengthened area 240 in top panel 200. Strengthened area 240 providestop panel 200 with added resistance to breaking or deforming at thepoint at which top panel 200 contacts the top edges of left side panels320, 420. Although FIG. 3 only shows one end of case 1, it is understoodthat the other end of case 1 can be similarly constructed.

As can be seen from FIG. 2, the various strengthened areas in thisexample can be produced in a sheet of corrugated plastic whose crosssection is not uniform in a transverse direction B but is uniform alongan extrusion direction A. Because of this, the sheet of corrugatedplastic shown in FIG. 2 can be cut from a sheet of corrugated plasticproduced by extrusion.

FIG. 5 shows an alternate embodiment of the invention in whichstrengthened areas 440′ and 445′ are corrugated, and non-strengthenedareas are thin solid plastic sheets. Depending on the intended use ofthe case, the embodiment shown in FIG. 5 may provide sufficient strengthwhile using less plastic.

FIG. 6 shows an embodiment of the invention including a cornerreinforcement 500 that can be formed during the extrusion process as apart of, in this example, left side panel 420 and can be bonded to backpanel 400 during assembly of case 1. Corner reinforcement 500 canprovide added strength to the corners of case 1 and, thereby, allowreduction of the amount of plastic used in other sections of case 1while maintaining the required strength. Similarly, a rib can be formedduring extrusion on one or more of the panels in, for example, a centralregion of the panel to provide structural support for the case.

In the examples shown in the Figures, the left and right ends of case 1are designed to be the primary load carrying members in the case.However, depending on the intended use of the case, different sectionscan be made stronger as appropriate. Also, the case and bottles to becarried in the case can be designed together so that sufficient strengthis provided by the combination of the case and the bottles.

The various fold lines of the invention are preferably formed during theextrusion process so that no further scoring is necessary beforeassembly.

The embodiments illustrated and discussed in this specification areintended only to teach those skilled in the art the best way known tothe inventors to make and use the invention. Nothing in thisspecification should be considered as limiting the scope of the presentinvention. All examples presented are representative and non-limiting.The above-described embodiments of the invention may be modified orvaried, without departing from the invention, as appreciated by thoseskilled in the art in light of the above teachings. It is therefore tobe understood that the invention may be practiced otherwise than asspecifically described.

1. A plastic corrugated case, comprising: at least one extruded sheethaving, in an unfolded state, an extrusion direction and a transversedirection perpendicular to the extrusion direction, the sheet having across-sectional profile parallel to the transverse direction, thecross-sectional profile having a first section, and a second sectiondifferent from the first section.
 2. The case of claim 1, wherein thesheet further comprises: a first panel; and a second panel attached tothe first panel, wherein a cross-section of at least one of the panelsis partially the first section and partially the second section.
 3. Thecase of claim 2, wherein the second panel attaches to the first panelalong a fold line.
 4. The case of claim 3, wherein the fold line isparallel to the extrusion direction and is part of the cross-sectionalprofile.
 5. The case of claim 3, wherein the fold line is parallel tothe transverse direction.
 6. The case of claim 3, wherein the firstsection is a corrugated cross-section.
 7. The case of claim 6, whereinthe second section is a corrugated cross-section that is stronger thanthe first section.
 8. The case of claim 6, wherein the second section issolid.
 9. The case of claim 2, wherein the cross-sectional profile has aprotrusion that, when the sheet is in a folded state, forms a cornerbrace between the first panel and the second panel.
 10. The case ofclaim 2, wherein the cross-sectional profile has a protrusion that, whenthe sheet is in a folded state, forms a structural rib on one of thefirst panel or the second panel.
 11. The case of claim 3, wherein theentire case is formed from one piece of the extruded sheet.
 12. A onepiece plastic corrugated case having, in an unfolded state, an extrusiondirection, the case comprising: a bottom panel having a cross-sectionalprofile perpendicular to the extrusion direction; a front panel attachedto the bottom panel and having a cross-sectional profile perpendicularto the extrusion direction; a back panel attached to the bottom paneland having a cross-sectional profile perpendicular to the extrusiondirection; a right side panel attached to at least one of the frontpanel, the back panel or the bottom panel and having a cross-sectionalprofile perpendicular to the extrusion direction; a left side panelattached to at least one of the front panel, the back panel or thebottom panel and having a cross-sectional profile perpendicular to theextrusion direction; and a top panel attached to at least one of thefront panel, the back panel, the right side panel or the left side paneland having a cross-sectional profile perpendicular to the extrusiondirection, wherein the case is, in the unfolded state, a single piece ofplastic, and at least one of the cross-sectional profiles changes alonga direction perpendicular to the extrusion direction.
 13. The case ofclaim 12, wherein, in the unfolded state, the right side panel comprisesa front right side panel attached to the front panel, and a back rightside panel attached to the back panel; and the left side panel comprisesa front left side panel attached to the front panel, and a back leftside panel attached to the back panel.
 14. A method of producing aplastic corrugated case, the method comprising: extruding a first sheethaving, in an unfolded state, an extrusion direction and a transversedirection perpendicular to the extrusion direction, the extrusioncausing the first sheet to have a cross-sectional profile parallel tothe transverse direction, the cross-sectional profile having a firstsection, and a second section different from the first section; foldingthe first sheet to form at least a part of the case; and attachingportions of the first sheet to other portions of the first sheet or toportions of a second sheet to maintain the case in a folded state. 15.The method of claim 14, wherein the first sheet is extruded to furthercomprise: a first panel; and a second panel attached to the first panel,wherein a cross-section of at least one of the panels is partially thefirst section and partially the second section.
 16. The method of claim15, wherein the first sheet is extruded such that the second panelattaches to the first panel along a fold line.
 17. The method of claim16, wherein the fold line is parallel to the extrusion direction and ispart of the cross-sectional profile.
 18. The method of claim 16, whereinthe first section is extruded as a corrugated cross-section.
 19. Themethod of claim 18, wherein the second section is extruded as acorrugated cross-section that is stronger than the first section. 20.The method of claim 18, wherein the second section is a solid extrusion.